DHA对高脂饲粮诱导肝脏脂肪积累的预防作用

【目的】探索二十二碳六烯酸(DHA)对高脂饲粮诱导肝脏脂肪积累的预防机制。【方法】将32只雄性SPF级C57BL/6小鼠均分为4组,对照组(Con)饲喂普通饲粮,模型组(Model)饲喂高脂饲粮,DHA组分别在高脂饲粮中添加0.2 g DHA(DHAL)和1.0 g DHA(DHAH),饲喂周期为20周。饲喂期间每天称量体重及食物重量,计算摄食量;饲喂结束,采集肝脏和血液,ELISA法检测肝脏脂联素和血清甘油三酯(TG)的含量,实时荧光定量PCR检测新生脂肪合成关键酶(SREBP-1c、FAS)、脂肪酸氧化关键基因(PPARα、PPARγ、CPT-1A和ACOX)、线粒体基因(PGC-1α)、褐色脂肪化基因(Prdm16、UCP1)的表达,Western blotting法检测肝脏磷酸化ACC、AMPK和AKT蛋白的表达。【结果】与Con组相比,Model组终体重、体脂重量和TG含量均显著增加(P<0.05),肝脏脂联素浓度显著降低(P<0.05)。与Model组相比,DHAL和DHAH组终体重、体脂重量和TG含量均显著降低(P<0.05),肝脏脂联素水平显著增加(P...

Preventive Effect of Docosahexaenoic Acid on Liver Lipid Accumulation Induced by High Fat Diet in Mice

Objective] This study was to explore the preventive mechanism of docosahexaenoic acid (DHA) on liver fat accumulation induced by high fat diet (HFD). Method] 32 male mice were divided into 4 groups. Control group (Con) mice were fed with control diet, model group (Model) mice were feed with high fat diet, DHA groups were supplemented with 0.2 g DHA (DHAL) and 1.0 g DHA (DHAH) in high fat diet, respectively. The feeding cycle was 20 weeks. The body weight and diet weight were weighed during feeding, and the food intake was calculated. At the end of feeding, liver and blood were collected, and the contents of liver adiponectin and serum triglyceride (TG) were detected by ELISA. The expression of key enzymes of newborn lipogenesis (SREBP-1c, FAS), key genes of fatty acid oxidation (PPARα, PPARγ, CPT-1A and ACOX), mitochondrial gene (PGC-1α) and brown fatty genes (PRDM16, UCP1) were detected by Real-time quantitative PCR. The expression of the hepatic phosphorylated ACC, AMPK and AKT proteins were determined by the Western blotting. Result] Compared with Con group, the final body weight, body fat weight and TG content were significantly increased (P<0.05), and hepatic adiponectin level was significantly decreased in Model group (P<0.05). When compared with Model group, the final body weight, body fat weight and TG content of DHAL and DHAH groups were significantly decreased (P<0.05), and liver adiponectin level was significantly increased(P<0.05). The results of Real-time quantitative PCR showed that compared with Con group, SREBP-1c and FAS mRNA level of Model group were significantly increased (P<0.05), PPARα, CPT-1A, ACOX, PGC-1α and UCP1 mRNA level of Model group were significantly decreased (P<0.05). While compared with Model group, SREBP-1c and FAS mRNA levels of both DHAH and DHAL groups were significantly decreased (P<0.05), and the level of DHAH group was lower than that of DHAL group (P<0.05), PPARα, CPT-1A, ACOX, PGC-1α, Prdm16 and UCP1 mRNA expression level of DHAL and DHAH groups were significantly increased (P<0.05), CPT-1A and ACOX mRNA level of DHAH group was higher than that of DAHL group (P<0.05), and there was no significant difference in PPARγ mRNA expression level among the four groups(P>0.05). The results of Western blotting showed that p-ACC in Model group was significantly higher than that in Con and DHAH groups, but significantly lower than that in DHAL group, p-AMPK/AMPK and p-AKT/AKT of Model group were smaller than those of Con group (P<0.05), p-AMPK/AMPK and p-AKT/AKT of DHAH group were bigger than those of Model and DHAL groups (P<0.05). Conclusion] DHA could reduce the increase of final body weight, body fat and TG content in C57BL/6 mice caused by high fat diet, promote fatty acid oxidation and browning of white adipocytes, so as to prevent fat accumulation in liver.